/*

  This file should always be included *first* in a web page,
  so we can use the same arrays (imgOff, imgOn, etc) elsewhere

*/

function pass(){
 // do nothing
}

var js_staticdir = "/images/";

var loaded = false;

var imgOff = new Array();
var imgOn = new Array();
var imgNull = new Array();
var imgToggledOn = new Array();

function preload(imgs, rollover_ext) {
  n = 0 ;
  img = '' ;
  if ( document.images ) {
    for ( n = 0; n < imgs.length; n++ ) {
	    img = imgs[n] ;
      imgoffsrc = js_staticdir + img + ".gif";
	    imgonsrc = js_staticdir + img + rollover_ext + ".gif";
      imgOff[img] = new Image();
      imgOff[img].src = imgoffsrc;
      imgOn[img] = new Image();
      imgOn[img].src = imgonsrc;
      imgToggledOn[img] = false;
    }
  }
}

function tabOff(tab) {
  // we simply don't bother with netscape...
  if ( document.all ) {
    document.all[tab].background = js_staticdir + "dark_tab.gif";
  }
}

function tabOn(tab) {
  // we simply don't bother with netscape...
  if ( document.all ) {
    document.all[tab].background = js_staticdir + "light_tab.gif";
  }
}

function rollOn(img) {
  img_name = img;
  if (document.images && loaded && !imgToggledOn[img_name] && imgOn[img_name] ) {
    document.images[img].src = imgOn[img_name].src;
  }
}

function rollOff(img) {
  img_name = img
  if (document.images && loaded && !imgToggledOn[img_name] && imgOff[img_name] ) {
    document.images[img].src = imgOff[img_name].src;
  }
}

// needless repetition for backwards compatibility
function rollOnName(img, img_name) {
  if(imgOn[img_name]) 
    img.src = imgOn[img_name].src;
}

function rollOffName(img, img_name) {
  if(imgOff[img_name]) 
    img.src = imgOff[img_name].src;
}

function toggle(img) {
  if (document.images) {
    if (imgToggledOn[img]) {
      document.images[img].src = imgOff[img].src;
    } 
    else {
      document.images[img].src = imgOn[img].src;
    }
  }
  return true;
}